BLACK ROCK, CITY OF

NPDES permit AR0037508 · Minor POTW · administratively continued, expires 2025-10-31 · EPA's file as of 2026-09-19

Check this month's numbers before you file

This permit expired on 2025-10-31 and is administratively continued: its last limits keep applying until a new permit is issued, and EPA still expects the reports.

EPA's record, 2025-09-01 to 2026-08-31

1values over a limit
0required values missing, on 0 form(s)
3of 11 forms filed late

Last period with anything received: 2026-07-31. Most often over: Chlorine, total residual (1).

Reporting

Reports are due about 25 days after each monitoring period ends (read off this permit's own late-day counts in EPA's filings).

Limits in force (29)

OutfallParameterStatisticLimitMonths
001Oxygen, dissolved [DO]INST MIN >= 4 mg/L May, Jun, Jul, Aug, Sep, Oct
001Oxygen, dissolved [DO]INST MIN >= 2 mg/L Jan, Feb, Mar, Apr, Nov, Dec
001pHMINIMUM >= 6 SU all year
001pHMAXIMUM <= 9 SU all year
001Solids, total suspendedMO AVG <= 90 mg/L all year
001Solids, total suspended7 DA AVG <= 135 mg/L all year
001Solids, total suspendedMO AVG <= 120 lb/d all year
001Nitrogen, ammonia total [as N]MO AVG <= 14.7 mg/L Jan, Feb, Mar, Nov, Dec
001Nitrogen, ammonia total [as N]MO AVG <= 10 mg/L May, Jun, Jul, Aug, Sep, Oct
001Nitrogen, ammonia total [as N]MO AVG <= 5.2 mg/L Apr
001Nitrogen, ammonia total [as N]7 DA AVG <= 14.7 mg/L Jan, Feb, Mar, Nov, Dec
001Nitrogen, ammonia total [as N]7 DA AVG <= 15 mg/L May, Jun, Jul, Aug, Sep, Oct
001Nitrogen, ammonia total [as N]7 DA AVG <= 5.2 mg/L Apr
001Nitrogen, ammonia total [as N]MO AVG <= 20.2 lb/d Jan, Feb, Mar, Nov, Dec
001Nitrogen, ammonia total [as N]MO AVG <= 13.8 lb/d May, Jun, Jul, Aug, Sep, Oct
001Nitrogen, ammonia total [as N]MO AVG <= 7.2 lb/d Apr
001Flow, in conduit or thru treatment plantMO AVG report only all year
001Flow, in conduit or thru treatment plantDAILY MX report only all year
001Chlorine, total residualINST MAX <= .011 mg/L all year
001Coliform, fecal general30DA GEO <= 1000 #/100mL all year
001Coliform, fecal general7 DA GEO <= 2000 #/100mL all year
001OverflowsMO TOTAL report only all year
001Overflow volume [SS0 volume, CSO volume]MO TOTAL report only all year
001BOD, carbonaceous [5 day, 20 C]MO AVG <= 18 mg/L May, Jun, Jul, Aug, Sep, Oct
001BOD, carbonaceous [5 day, 20 C]MO AVG <= 25 mg/L Jan, Feb, Mar, Apr, Oct, Nov, Dec
001BOD, carbonaceous [5 day, 20 C]7 DA AVG <= 27 mg/L May, Jun, Jul, Aug, Sep, Oct
001BOD, carbonaceous [5 day, 20 C]7 DA AVG <= 38 mg/L Jan, Feb, Mar, Apr, Oct, Nov, Dec
001BOD, carbonaceous [5 day, 20 C]MO AVG <= 25 lb/d May, Jun, Jul, Aug, Sep, Oct
001BOD, carbonaceous [5 day, 20 C]MO AVG <= 34 lb/d Jan, Feb, Mar, Apr, Oct, Nov, Dec

Built from EPA's ECHO bulk files. EPA's file, not the permit document, is the source: read your permit. Check a report before you file it · All states